Fuel-oil burner.



PATENTED JULY 16, 1907.

P. SMITH. FUEL on. BURNER. APPLICATION FILED AUG. 31. 1906.

ooooooo OOO gnou/dez UNITED sTATEs PATENT OEEIOE.

FORBES sMiTH, OF TAGOMA, WASHINGTON, AssiGNOP. TO REUBEN SMITH, or PORTLAND,

' OREGON. f

FUEL-OIL BURNER.

No. sedano.

Specification of Letters Patent.

Patented July` 1e, 1907.

Application filed August 31, 1906. ,Serial No. 332,849. v

To all whom it may concern:

B it vknown that I, FORBES SMITH, a.c1tizen of the United States of America, residing at Tacoma, in the county of Pierce and State of Washington, have inventedcertainnew and use ful Improvements in Fuel-Oil Burners, of which the following is a specification, rel'crence being had therein to the accompanying drawing.

This invention relates to fuel oil burners, and.- has for 'its objects to .increase the efficiency of such burners and also to simplify them. g'

:I attainthese .objects by the devices illustrated in theaccompanying drawing,l in which 1 is an elevation, and Fig. 2 is a longitudinalr section ofthe burner: Fig. 3 is a cross-section on the line 3-3 in Fig. 2, and Fig. 4 is an end elevation of the l inner oil tube cap.

- lSimilarnumerals ofreference refer to similar part throughout the several views. l

The main casting 1 is circular in cross-section and has an annular closed chamber 2 aroundits center,

and also a central chamber 3. The chambers 2.

and 3 are connected, together by several passages 45. passing through the wall 5 which .separates them.- A rontextension 6 is formed on the casting 1 andl has a cavity therethrough extending from the central chamber 3 and of somewhat larger diameter.'

` Ps 7 connect the chamber-2 with the cavity l in the extension 6 The chamber 3 and the cav- .ity in extension 6 are screw-threaded to receive the inner and outer tubes ofthe burner, respectively. The rear oi the casting l is also provided with an exten- .sion.8 havinga screw-threaded hole therethrough v entering said central chamber 3. The outer surface o f. said-.rear extension 8 is screw-threaded toA receive the `ianged union 9 which clamps the flangedpreceiving joint l0 into which the oil feed pipe screws. .A tapped hole 1l passes through the A casting l, into the annular chamberA 2 and is adapted to receive the pipe through which the steam or compressed air is fed under pressure.. The oil supply tube l2. screws into and through therear extension 8 and alittle more than half way through the central .chamber -3.. A preliminary mixing cham- 'ber'.is formed beyond saidtube 12 by screwinga tube A13 into'the end of-the said chamber 3, said n .tube being closed at its ront'or outer end by the cap sides.

14, but having a serio; oi outlet holes 15 in its An intermediate nl .g chamber is formed outside oi thelsaid tube 13 by an'outer tube 16,

' with a flange 17 around itsend and'notches 18,.-

' aremade in its periphery. The cap. 14 fits neatlywhich screws into the cavity in the front extension 6, said tube 16. extending over and beyond said tube 133. "*The'cap 14 of the tube 13 is provided is vtoorsloyvff the tube 16 and closes the said intermediate mixing chamber except for the notches 18, through which the mixed oil and air, or steam, passes. The tube .16, as above stated, extends beyond the cap 14 and'iorms at its outer end the final mixing chamber by havingthe head 19 screwed thereon. The delivery slot 20 is made through the center of the head 19 Within this final mixing chamber I place` the spiral -defiector 21, which `consists of a spirally twisted to the tube l2 by way of the joint 10, and air or' steam under similar pressure is delivered to the annular chamber 2 by way of the tapped hole l1. Some of the air or steam passes through the passages 4 into 'the' chamber 3 at a point slightly to the rear of the end of the oil tube 12. This air and oil are then forced bytheir pressuresinto the preliminary mixing chamber on the inside of the tube -13. The only outlet from this chamber is by way of the holes 15 through the sides 'of the tubefl so that as the outlet is atright angles to the direction of the flow at )the entrance to the chamber `a considerable amount of mixing takes place inthis chamber and in the process of escaping therefrom. A further supply of air passes directly from theehamber 2 'by the passages 7 j into the intermediate mixing chamber between the tubes 13 and 16. This air travels longitudinally.

of said chamber, though directed by the passages"7 towardl the outer surface of the vtube 13, and meets at each of the holes l5 the'preduCi 0f the preliminary mixing on the inside of said tube 13 and mixes therewith. This mixing is quite complete since itmeets the partial mixture at right anglesi The mixture new passes through the notches 18 in the rim ,Y

' 17` of th'elcap 14. The tendency has been in the mixing in the above two chambers to allow the heavier parts of the mixture to falll to the lowers parts "of the chambers and thereforeto make a slight difference be. tween the mixtures in the upper andv lower parts thereof.' To urtliencomplete the mixing 'a spiral motion to the-mixture byxnearis'oifthespiral metal piece 21 Z and -1 provide on vits, suracesa number oi sharp projectlions 22 Awln'chpcut',into any viscous Awhich"haslbeen carried in with the oil; but which break p and. become JAL" ts moveme The spiral mixer .having given a rotary motion to the mixture, a final and complete mixing occurs Within said end chamber, especially as the outlet therefrom is preferably made by, a straight slot, thuscausing a further charge of motion and resulting in a further 'mixture y I find that when myxburner isi-used that the blue flame starts very close to the slot 20, whereas in all the'burners which I have seen the ane doesnot start for some distance, showing conclusivelythat in those instances the mixing hasvbeen very incomplete and occurs mostly after the oil has left the burneigwhile in my burner the oil is properly and completely mixed before leaving the burner. Further, on account ofthe complete mixing ofthe oil and air, and on account of the cutting up of the viscous matter Vin the oil by the sharp edges, I find that the usual deposit of powdery carbon within the burner is entirely absent in my burner, and that it does not require to be taken apart for periodical cleaning, as it keeps itself clean.

Having, therefore, fully described the construction and operation of my invention, what I claim is:

1. In a fuel oil burne1', the combination of an exterior annular' mixing chamber with outlet passages at its end, air supply passages entering said chamber at its other end, an rinterior tubularmixing chamber within said exterior' chamber and having outlets thereinto by 'holes in its sides at right angles to the flow in said exterior chamber," an oil supply tube entering said interior mixing.

lend, air supply passages entering said :interior mixing .chamber around said oil supply tube, an exterior annular mixing chamber'with circumferential outlet-passages at its end into an end mixing chamber, air supply passages 'entering said annular hamber at its other end, an end mixingchamber having a central outlet therefrom, and a spiral deflector Within said end chamberto impart a rotary motionto the mixture therein.

4. In a fuel oil burner, the combination of an interior lets into an exterior chamber by holes in its sides,pan oil supply tube entering said interior mixing `chamber at one end, air supplypassages. entering said interior mixing chamber around said oil supply tube, an exterior` annular mixing chamber with circumferentia outlet passages at its end into an end mixing chamber, air supply passages entering said annular chamber at its other end, .an 'end mixing chamber having a central outlet therefrom, a spiral dee ctor.within said chamber to impart a rotary. motion to the mixture therein, and 'cutting projections formed on said spiral deector to intercept and cut viscous matter in the oil.

'tubular mixing chamber closed at its end and having out- 5. In a fuel oil burner, the combination of a casting i formed with an annular air chamber and a central chamber with passages leading from said. annular chamber to `said central chamber and passages leading from saidannular chamber to a ca vity outside said central chamber; an outer tube outside of said second passages; an inner tube inside said outer tube and entering said central chamber and having outlet holes in' its sides but a closed end; a spiral defiector in saidvrouter-tube beyond said inner tube; and a-burner head on said outer tube with a 4FORBES sM'rH.

Witnesses l M. H. Conny, W. M. KENNEDY. 

